Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
Each channel running on the Roku system is created, provided, and maintained by the people at that channel, who also decide and program its features. Roku only provides the platform on which the 3rd party channel apps run. If you want American Voice to have a channel on Roku you need to communicate this to them.
Edit: Nevermind. I see they already have a Roku channel: